| Joined: | Wed Apr 18th, 2012 |
| Location: | United Kingdom |
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As you know when taking recent holiday shots with the Fuji I struggled with hotspotting on my available lens.
The Fuji shot shows a hotspot despite my attempt to minimise it with aperture and focal length choice.
If you bang the saturation up to maximum you can more clearly see this central anomaly and more annoyingly, its a blue colour. This anomaly therefore not only introduces an optical flaw but a chromatic shift...which when you start messing with colours can reeeaaally slew the result across the image.
Its also puzzling why the hotspot IS blue? Does this mean the anomaly happens at the sensor rather than in front of the IR filter? Why would it respond differently in colour if it was just internal lens glass reflection????
I saw this phenomena some time ago and incorporated this knowledge into my hotspot removal sequence.
FYI
KNOWING the hotspots are blue-magemnta I first try to eliminate these colours from the image (hence the desire to shift to a yellower overall tint). Essentially that is nothing more than using hue/sat set to blue and then magenta channels, decreasing saturation AND modifying the lightness to balance some of the exposure difference to the rest of the image. Once that's done I can mask to correct the slight over exposure in the centre of the image.
Only then I can get on with the normal messing about.
:thumbsup:
Attachment: hotspot.jpg (Downloaded 28 times)
Last edited on Wed Aug 13th, 2014 05:18 by Eric
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Eric